Ship Driver Navigation and Chart Reading

Question 1

What does a nautical chart's depth sounding number represent?

Accepted Answer

Water depth at low tide

Answer

Nautical chart depth soundings represent the water depth measured at mean lower low water (MLLW), the average of the lowest daily tides.

Question 2

What color are safe water marks (mid-channel buoys) in the US system?

Accepted Answer

Red and white vertical stripes

Answer

Safe water marks (mid-channel buoys) feature red and white vertical stripes, indicating navigable water on all sides.

Question 3

When entering a US port from seaward, where should red buoys be?

Accepted Answer

On your right (starboard side)

Answer

The US IALA-B system follows 'red right returning,' meaning red buoys are kept to starboard when entering port from sea.

Question 4

What is a compass rose on a nautical chart used for?

Accepted Answer

Reading true and magnetic bearings

Answer

A compass rose shows both true north (outer ring) and magnetic north (inner ring) so mariners can convert between the two for navigation.

Question 5

What does the abbreviation 'RK' indicate on a nautical chart?

Accepted Answer

Rocky bottom

Answer

'RK' on a nautical chart indicates a rocky bottom or rock hazard, warning mariners of potential grounding danger.

Ship Driver Practice Test